Recently, with the development of network techniques and the wide spread of networks, data amount in the world has increased in an explosive manner. The amount of data is so huge that enterprises have to adopt mass data storage systems. At the same time, in order to provide superior services to clients, powerful security has become an extremely important aspect for those mass data storage systems. Such storage systems may incur inestimable losses even if they stop their services for 1 minute. Thus, a secure and reliable data disaster tolerance technique is highly desired.
A distributed structural storage architecture is commonly adopted in the prior art, wherein a distributed structural network is constructed by a plurality of nodes, each node maintains information about most other nodes, and a predefined protocol is configured to maintain the structural relation among those nodes, that is, each node randomly selects another node per second to send it a message to negotiate their records of system node variation with each other and update their node lists. Each node is responsible for managing a piece of index and arranges its backup on each of N consecutive and successor physical nodes.
However, the inventors of this disclosure have found that the prior art has at least the following issue: when node failure occurs, there is a possibility of unable to completely recover all index information that has been lost.